THe United Nations Inter-Governmental Panel on Climate Change predicts that flooding will intensify as greenhouse gas concentrations in the atmosphere increase. What this implies is that we have to be prepared for more flood disasters.
A former President of the Ikeja branch of the Nigerian Society of Engineers, NSE, Kunle Adebajo, noted that the water level in Lagos is high and it is to a large extent, surrounded by water.
“The topography of the city is relatively flat and flat terrains do not give much room for the design and construction of proper functional self cleaning drains in terms of minimum allowable slopes. In such a situation, very deep drain sections would normally be required and yet the high water table does not facilitate this. This is generally the reason behind having shallow drains in the Lagos environs,” he said.
The former president of the Nigerian Institution of Structural Engineers, NIStructE, stated that forces of nature are against a city like Lagos.
“Apart from the ground, majority of the water would normally be expected to be channelled towards storm water outfalls. The main out falls for storm water runoff in Lagos are the canals and the lagoons. Unfortunately, they are also characterised by high water level. In addition, the existing condition of the main storm water outfalls is very poor and most of the canals are stagnant. Illegally located buildings and structures will need to be demolished and this would mean that the people will be displaced.
“The drainage system will, however, be dramatically improved and considering the benefit to all who live in Lagos and indeed the benefits to the economy of the entire nation, this is by no means too great a sacrifice to make,” he said. Adebajo, an engineer, who is the Senior Partner of Ovie Arup & Partners ( a firm of structural engineers), called for an enduring engineering solution to the problem of flooding in the country.
He canvassed the construction of more drainage structures to complement existing ones which should be kept functional. A proper storm water drainage master plan, he said, should be prepared for the city and this should be faithfully implemented. According to him, only qualified civil/structural engineers should be involved in the design and execution of such projects.